This invention relates to hemodialysis and it has particular relationship to implantable port assemblies through which toxified blood of a patient is replaced by detoxified blood in the practice of hemodialysis. Notwithstanding that there is substantial demand for implantable hemodialysis apparatus, the availability of such apparatus, in accordance with the teachings of the prior art, is limited. Typically, as disclosed in Shill U.S. Pat. No. 3,791,767, the interchange of detoxified blood for toxified blood is effected through a hypodermic needle which is inserted in a vein (or artery) in the body. An implantable device is disclosed in Constantino U.S. Pat. No. 4,496,350. This device includes a stem which extends outwardly from the body of the host. The patient is subjected to serious inconveniences. For example, the end of the device which extends from the skin must be taped over with great care when the patient is bathing so that water does not penetrate through the joint between its outer surface and the skin. There is also an ever-present danger of infection. In accordance with Constantino's teaching, the flow channels of the device must be spliced into the vein or artery of the patient through which the blood interchange takes place.
It is an object of this invention to overcome the drawbacks and disadvantages of the prior art in the practice of hemodialysis and to provide for the interchange of toxified and detoxified blood of a patient through an implanted hemodialysis port assembly which shall not subject the patient to the inconveniences, hazards and disfigurement involved in the teachings of the prior art.